iodine

[ ahy-uh-dahyn, -din; in Chemistry also ahy-uh-deen ]

nounChemistry.
  1. a nonmetallic halogen element occurring at ordinary temperatures as a grayish-black crystalline solid that sublimes to a dense violet vapor when heated: used in medicine as an antiseptic. Symbol: I; atomic weight: 126.904; atomic number: 53; specific gravity: (solid) 4.93 at 20°C.

Compare Meanings

Click for a side-by-side comparison of meanings. Use the word comparison feature to learn the differences between similar and commonly confused words.

Origin of iodine

1
First recorded in 1814; from French iode + -ine2 (def. 2); introduced by H. Davy. Ultimately from Greek īṓdēs, originally “rust-colored”, but by folk etymology taken as í(on) “violet” + -ōdēs noun suffix; see -ode1
  • Sometimes i·o·din [ahy-uh-din]. /ˈaɪ ə dɪn/.

Words Nearby iodine

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use iodine in a sentence

British Dictionary definitions for iodine

iodine

/ (ˈaɪəˌdiːn) /


noun
  1. a bluish-black element of the halogen group that sublimates into a violet irritating gas. Its compounds are used in medicine and photography and in dyes. The radioisotope iodine-131 (radioiodine), with a half-life of 8 days, is used in the diagnosis and treatment of thyroid disease. Symbol: I; atomic no: 53; atomic wt: 126.90447; valency: 1, 3, 5, or 7; relative density: 4.93; melting pt: 113.5°C; boiling pt: 184.35°C

Origin of iodine

1
C19: from French iode, from Greek iōdēs rust-coloured, but taken to mean violet-coloured, through a mistaken derivation from ion violet

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for iodine

iodine

[ īə-dīn′ ]


I
  1. A shiny, grayish-black element of the halogen group. It is corrosive and poisonous and occurs in very small amounts in nature except for seaweed, in which it is abundant. Iodine compounds are used in medicine, antiseptics, and dyes. Atomic number 53; atomic weight 126.9045; melting point 113.5°C; boiling point 184.35°C; specific gravity (solid, at 20°C) 4.93; valence 1, 3, 5, 7. See Periodic Table.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.